1. Field of the Invention
The present invention relates generally to fluorometers, and more particularly to a system and method for performing automated fluorescent measurements.
2. Related Art
Conventional medical devices used to perform fluorescent readings are large, dedicated machines. Typical fluorometers are bench-top devices which are not easily transported from location to location. Additionally, conventional fluorometers are not easily capable of being programmed by the user or otherwise configured by the user to perform a plurality of different types of tests. Instead, the conventional fluorometer is factory-programmed to perform a predefined test protocol.
To perform a test using a conventional fluorometer, a laboratory technician obtains a sample. The sample can be a biological fluid, such as blood, serum, plasma, urine, a fecal extract and the like or it can be an environmental sample, such as water, a ground extract, a chemical and the like or it can be an extract of a food product. In the case of a blood sample, the blood is first separated into plasma or serum, which becomes the sample, and cellular fractions using a centrifuge. The sample is then generally deposited into a small test tube that is inserted into the fluorometer. Because the conventional fluorometer can accept several samples, the technician enters an identification of the sample and the location of the test tube into the fluorometer.
Once one or more test tubes containing samples are positioned in the fluorometer, the test begins. Contemporary fluorometers use robotics to pipet the sample and the reagents and to position one or more optical sensors by the sample to obtain the necessary readings. The readings are recorded along with the associated test-tube location designations. The location designation is used to identify the sample.
The present invention provides a system and method for performing automated fluorometry. According to the invention, a fluorometer is provided which includes functionality to provide enhanced operational characteristics for the measurement of analytes in a sample. The system and method has particular importance as a laboratory or non-laboratory tool for rapidly and conveniently measuring analytes by skilled laboratorian or by individuals who are unskilled as laboratorians. According to one or more embodiments of the invention, the fluorometer can include an optical block, a removable storage medium, an internal processor, a communications interface, and internal data storage.
The system and method generally comprises the fluorometer and a testing or assay device. The assay device is used in conjunction with the fluorometer to achieve a result regarding the concentration or presence of an analyte in a sample. Examples of analytes include chemicals, proteins, peptides, bacteria, viruses, nucleic acids, cellular organelles, cells, receptors and the like. The assay device can include reagents that are necessary for performing an immunological or chemical reaction, such reaction giving rise to a change in fluorescence of the sample that has been treated with the reagents. The reagents can include chemicals, antibodies, peptides, analytes, analyte analogues and these reagents may or may not be coupled to fluorescent labels or to solid phases.
In one embodiment, the removable storage medium is implemented utilizing a ROM chip or other memory device, which can be interfaced to the fluorometer to provide operating instructions as well as calibration curves and control and calibration data. Preferably, the memory device is mounted on a carrier which provides easy insertion and removal such that a plurality of memory devices containing specific sets of data can be easily interchanged. In this manner, the fluorometer can be easily programmed and re-programmed to perform a variety of tests and calibrations.
Additionally, the removable storage medium can be implemented using a removable medium such as a disk and disk drive. The disk can contain test data sets for one or more types of tests to be performed. The test data sets can include test instructions and calibration curves for the test, as well as other program information and calibration and control information for the instrument.
A communications interface can be included to facilitate communications between the fluorometer and one or more other devices. The communications interface can include a wired and wireless interface to provide direct or networked communications. The communications interface can be used to download test data sets, including, for example, test identifications, test instructions and calibration curves, as well as other program information and calibration and control information. The communications interface can also be used to allow the fluorometer to share processing responsibilities with other devices such as a computer or other processor. Such an interface (wired or wireless) can be implemented, for example, utilizing an RS-232, infrared or modem interface for direct connection, or a network interface for network communications to one or more processors.
In one operational scenario, the communications interface is used to allow a physician or other health care professional at a health care facility (e.g., a doctor""s office, clinic, testing center, hospital, or other health care site or facility) to transmit test instructions to the fluorometer with regard to which tests are to be performed for a particular patient. The interface can also be used to forward test results to a health care facility to apprise the health care professional of the results. Results of tests and a catalog of tests performed can be sent to various locations for patient-diagnosis, record-keeping, billing, and other purposes.
In an alternative operational scenario, a patient can perform testing at home, and test results and instructions can be exchanged with a health care facility via the communications interface. In this embodiment, patients who require frequent monitoring can get the necessary tests without traveling to a health care facility each time a test is needed, for example, as may be required by patients taking daily regimens of therapeutic drugs.
In yet another operational scenario, a technician in the field can measure water or ground contamination and transmit the results to a home office via a cellular telephone or other communications medium to inform officials of the progress of a decontamination procedure.
Internal data storage can be used to store program instructions (including test instructions), calibration curves, control and calibration data as well as other data used in the operation of the fluorometer. Internal data storage can also provide register space for operand storage. Internal data storage can be implemented using, for example, RAM or DRAM technology, or other memory technology. Disk or other storage space can be used to supplement the internal data storage, depending on storage cost and access latency tradeoffs. Cache techniques can also be used to optimize performance.
Data storage, either internal or removable, can be used to store test information regarding a test or tests conducted or to be conducted on one or more samples. The test information can include information such as, an identification of the patient and other patient information, a sample identification, an identification of a test or tests performed on the sample, a date and time at which the tests were conducted, test conditions, test results, specific reagent information, such as lot numbers and expiration dates and other pertinent information. The test information can be stored in a record that can be indexed using, for example, the patient identification or other indexing designation.
Various user interfaces can be provided to facilitate user control and to enhance operability of the fluorometer. Input interfaces can include data entry devices such as a keyboard, keypad, touch-screen display, mouse, voice recognition input, or other data entry device. Output interfaces can include a display screen or monitor, printer, speaker or other output device.
The assay mechanism according to one embodiment includes a motorized mechanism for transporting the assay device in the fluorometer. Examples of such a motorized mechanism include, for example, those as described in U.S. Pat. No. 5,458,852 and U.S. patent application Ser. No. 08/458,276, now U.S. Pat. No. 5,922,615 titled xe2x80x9cDevices For Ligand Receptor Methods,xe2x80x9d which are incorporated herein by reference. The movement of the assay device in the fluorometer functions to position the diagnostic lane of the device with an optical block so that one or more fluorescent areas or zones of the assay device can be measured. The degree or presence of fluorescence in the diagnostic lane is related to the concentration or presence of analyte in the sample. The optical block can include a light source, detector and optics used to excite the sample as well as to sense the fluorescence of the excited sample. In one embodiment, the sample is disposed on the assay device. The assay mechanism can provide the capability to transport the assay device along the optical block such that fluorescence of one or more of a plurality of zones on the diagnostic lane of the device can be measured. As such, one advantage of the invention according to this embodiment is that enhanced testing algorithms can be utilized, if desired, in measuring the fluorescence of the sample.
An additional advantage of the invention is that the communications interface can be used to allow the fluorometer to be interfaced to networks such as, for example, a hospital or other health care facility network, or other information networks whereby the fluorometer can retrieve data which may be needed to conduct tests and download other data including the test results. Additionally, the communications interface can be used to interface with the fluorometer to a stand alone computer such as, for example, a personal computer or an office or a home office computer. In these configurations, the fluorometer can utilize the processing and peripheral capabilities of the stand alone computer or network resources to supplement its own processing and interface capabilities. In yet another configuration, the fluorometer can interface with an existing instrument that is interfaced to a network, such as, for example, an instrument in a hospital emergency department or critical care unit that dispenses medications for use by the hospital personnel. Interfacing the fluorometer to an existing instrument has advantages in that the interface of the fluorometer to the instrument can be one specific code, whereas the instrument interface code can be varied depending on the location of the instrument, for example, in different hospitals with different software interface codes.
For example, in one embodiment, the fluorometer can be operated as a portable hand-carried piece of test equipment that is used to test samples of blood. The portable, hand-carried unit can then be interfaced to a computer or computer network to upload test results or to simply communicate other data associated with the test and to use the processing power of the computer or computer network to perform some or all of the actual test processing. In yet another example, test data sets or other pertinent information can be downloaded from the outside entity to provide the fluorometer with guidance as to tests to be conducted on a particular sample. This guidance can be in the form of complete test instructions or simply an identification of a test to be performed for which the instructions are stored internally to the fluorometer. In another example, the data communicated to a network can be utilized in real time to diagnose and treat acute care patients.
Yet another feature of the invention is that it provides an encoded tag on the assay device such as, for example, a bar code label or magnetic strip to allow sample, test or reagent information to be encoded. Sample information can include, for example, an identification of the sample and sample type, an identification of the patient from which the sample was drawn, an indication of the test or tests to be performed for the sample, as well as other data, as desired. Reagent information can include the type of reagents in a device, lot specific information, such as calibration information and expiration dating. Once a sample is correctly labeled, there is no longer a need for manual user intervention to enter this information. In fully automated embodiments, this information is stored along with test results and other pertinent information to create and maintain an accurate record of the tests and test results. As such, the chance for operator error in incorrectly identifying a sample or otherwise incorrectly entering information regarding a test, is minimized. Additionally, test results and other data relating to the test can be automatically stored along with the patient identification and other associated information such that data for a patient can easily be accessed.
Another embodiment of the invention is to utilize an encoder, such as for example a magnetic strip encoder, in the instrument to encode information on an assay device. For example, patient information, including patient number, tests to be performed and the like can be entered through the keypad of the instrument or via a centralized computer that downloads the information to the fluorometer. The encoder records the information onto the assay device, such that when the user inserts the assay device into the fluorometer, a reader reads the information on the assay device and combines the assay results with the encoded information. The combined information can be stored in the fluorometer and it can be communicated to a network for real time or later analysis.
Yet another feature of the invention is that internal data storage can be provided so that patient information and test results can be tracked in the form of a history log. For example, in a portable hand-held environment, a user or technician may test several samples of blood in a given time interval. The test results, along with the identification of the patient, can be stored in the local database such that a history log of tests and test results are maintained. This history log can then be downloaded via the communications interface or onto a removable media.
Still another feature of the invention is that in remote or in-home applications, the identification of the patient can be based on an automatic number identification (referred to as ANI). In this embodiment, when the patient""s fluorometer dials the remote health care facility via a telephone network, the ANI signal provided by the telephone network is used by the health-care facility to identify the patient from which the communication originated. The ANI can be used in place of the an identification of the patient based on the encoded label, or in addition thereto to provide a cross check against potential identification errors.
Further features and advantages of the invention as well as the structure and operation of various embodiments thereof are described in detail below with reference to the accompanying drawings.